Knife-sharpener



J. RANZ.

KNIFE smnrsuen.

APPLICATION HLED JAN. 26, 1920.

Patented June 14, 1921.

JACOB RANZ, OF ST. LOUIS, IVEISSOURI.

KNIFE-SHARPENER.

Application filed January 26, 1920.

T Mi whom it may concern Be it known that I, JACOB RANZ, a citizen of the United States, residing at St. Louis, Missouri, have invented a certain new and useful Improvement in Knife-Sharpeners, of which the following is a full, clear, and exact description, such as will enable others 7 skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, forming part of this specification.

My invention relates to a knife sharpener of the type wherein an elongated cylindrical member of metal such as steel is provided with circumferentially disposed ribs or corrugations, and the latter being provided with abrading edges which are adapted to engage and act upon the surface of a blade when the latter is driven or moved lengthwise of the sharpening implement.

The principal objects of my invention are, to generally improve upon the existing types of similar forms of sharpening implements; and, further, to provide a knife sharpening device which may be easily and cheaply manufactured and which will be very effective in use and capable of very rapidly producing a sharp cutting edge on the blade of a knife or like tool.

lVith the foregoing and other objects in view, my invention consists in certain novel features of construction and arrangement of parts, hereinafter more fully described and Claimed, and illustrated in the accompanying dra ings, in which- Figure 1 is a perspective view of a knife sharpener of my improved construction.

Fig. 2 is an enlarged section taken a proximately on the line 22 of Fig. 1.

Referring by numerals to the accompanying drawings, which illustrate a. practical embodiment of my invention, 10 designates the body of my improved sharpener, the same having the form of a rod round in cross section and constructed of relatively hard metal, preferably steel. One end of this elongated cylindrical body is provided with a suitable handle 11 and the opposite or forward end may be tapered as designated by 12.

The greater portion of the periphery or surface of the body 10 is provided with circumferentially disposed grooves 13, thereby forming circumferentially disposed ribs 14:. These grooves 13 may be cut or formed so that they are parallel with each other, or a Specification of Letters Patent.

Patented June 14, 1921. Serial No. 354,148.

continuous spirally arranged groove may be formed on the surface of the body with a suitable threading die or the like. In either event, the groove or grooves should be formed so as to produce annular cutting edges 15, the latter being formed at the corners between the peripheral faces a of the rib l t and the surfaces Z2 at the forward ends of the grooves 13, and which last mentioned surfaces are disposed substantially at right angles to the peripheral surfaces at and likewise at right angles to the axis of the body 10. These annular cutting edges 15 are rearwardly presented, that is, they are presented toward that end of the implement that is provided with the handle 11 so that in sharpening the blade of a knife or like tool, said blade is applied to the ribbed body of the tool and moved longitudinally thereof or as indicated by the arrow 1n F 1g. 1.

While I prefer to form the grooves 13 with compound curved bottom surfaces connecting the inner portions with the peripheral surfaces at, as illustrated in Fig. 2, the particular contour or shape of these grooves can vary as desired.

lVhen a knife blade or the like is sharpened upon an implement of my improved construction, the best results can be obtained by holding the blade at a slight angle with respect to the axis of the body 10, as illustrated by dotted lines in Fig. 2, and while so positioned, the blade is moved forwardly or away from the handle 11 on the sharpening implement, and at the same time a slight pressure between the sharpening implement and blade is maintained, and as a result, the annular edges 15 will very rapidly abrade or wear away the surfaces of the knife blade adjacent to the edge thereof and consequently producing a sharp cutting edge.

It will be understood that the illustration in Fig. 2 is greatly enlarged and that in actual'construction, the grooves 13 and ribs 14: are very small; in fact, the best results are produced by forming the grooves but a few hundredths of an inch in width and depth.

A sharpening implement of my improved construction can be easily and cheaply produced, and as the abrading or cutting edges are disposed at right angles to the lines of travel of the blade during the sharpening operations, said implement will be very cfof the surfaces 5 feotive in rapidly performing its intended functions.

It will be readily understood that minor changes in the size, form and construction of the various parts of my improved implement can be made and substituted for those herein shown and described, Without departing from the spirit of my invention, the scope of which is set forth in the appended claim.

of which is provided with a groove, the surface of said groove at one side being disposed substantially at right angles to the axis of the body of the implement to form a substantially right angled cutting edge, and the opposite side ofsaid groove being curved upwardly to meet the surface of the body of the tool and form a rounded shoulder.

In testimony whereof I hereunto aflixmy signature this 16th dayof January, 1920.

JACOB RANZ. 

